Data from the Early Pregnancy Study (EPS) (A.Wilcox, PI) provide a resource for ongoing research into reproductive hormones, fertility, &early pregnancy. During field work for this study in 1982-1985, women enrolled at the time they stopped using birth control in order to conceive. We followed them through their 8th week of pregnancy. They collected daily first morning urine specimens and these were analyzed for human chorionic gonadotropin and steroid metabolites. Women with known fertility problems were excluded, so the sample represents normal unassisted reproduction. We conducted a pilot study to test the stability of hormones in urines stored from the Early Pregnancy Study. A subsample of urine specimens from the EPS have been analyzed for phthalates, and bisphenol A to see if those toxicants can be evaluated in these stored samples. Analysis shows similar distributions of these toxicants as reported for more recently-collected samples and similar within-woman reproducibility measures. This supports analysis of specimens from the complete EPS study in order to examine the relationship between these exposures and fertility and early pregnancy. We have designed the further exposure outcome analysis and further specimens have been sent to the CDC for analysis. We also would like to look further at hormonal changes during early pregnancy with the EPS urines, but do not know how well they can be measured after long-term storage. We collected a sample of new daily urine specimens during early pregnancy to serve as a reference to evaluate the quality of hormone data from the stored samples. Estrogen and progesterone metabolite as well as hCG measurements from a sample of the stored urines will be compared to these hormones measured in newly collected urine samples. We enrolled 44 women, 26 of whom became pregnant and collected daily first morning urine specimens. Urine samples from the new collection and stored EPS samples are being analyzed for estrogen and progesterone metabolites as well as for hCG by Jim Kesner at NIOSH. There is methodologic interest in quality of self-reported reproductive data, and there have been several efforts to evaluate the validity of such reports. We have evaluated the validity of self-reported cycle characteristics by comparing interview data to prospective daily recording of menstrual bleeding and pain. We have also examined the validity of self-report of bleeding during pregnancy. In another methodologic project, we are using available data to determine how well women can report the timing of their positive pregnancy test. Bias arises in spontaneous abortion &time-to-pregnancy studies when comparing exposed and unexposed groups that differ in timing of pregnancy testing. Those who tend to have delayed pregnancy testing will recognize fewer spontaneous abortions, and they will have longer times to pregnancy. I have done a comprehensive review of female fecundabilty studies (to be published as a book chapter in a new edition of Women &Health. We continue our research into factors affecting fertility. We are looking at pesticide exposure using data from the Agricultural Health Study. In addition, we have a special interest in female age-related decline in fertility. An ongoing prospective time-to-pregnancy study is providing data on antimullerian hormone as a potential marker of fecundability. The potential for this hormone to be used as an ancillary or primary outcome measure for studies of female fecundability needs further investigation, and the need for this new area of investigation has been presented in a commentary. We have examined the effects of early life exposures on both age of menarche and age of menopause using data from the Sister Study.